Self-centralizing and synchronizing device for arbor plug gauges



Aprll 6, 1954 H. RICE 2,674,146

SELF-CENTRALIZING AND SYNCHRONIZING DEVICE FOR ARBOR PLUG GAUGES FiledSept. 9, 1950 INVENTOR. lEO/VARD H. RICE BY /J%WA w Patented Apr. 6,1954 STATES ()FFICE YSELFBGENTRALIZING AND LSYN'CHRIONIZING' DEVICE FOR;ARBOR PLUG GAUGES Leonard Rice, manganese, assi nor a: one-half toKenneth E. Watson, Montague City, Mass.

Application September 9, 1950, Serial No. 183,949

1 Claim. 1 Y invention relates to a. self-centralizing arbor. andsynchronizing device for plug gages; either plain or threaded. I Atpresent,vpersonnel engaged in truing plug gages require about five yearsof training in order to turn out a plug age of high quality in areasonable time. I itis an object of the instant invention to provide adevice for truing plug gages with which the inexperienced can performthe work now performed by the highly skilled. I

A further object is to decrease costs in the manufacture of plug gages.Other objects of the instant invention will become apparent inthe-course of the following specification.

In the attainment of these objectives, the caserelative to the ends ofthe plug and is used asa synchronizing device.

The invention will appear more clearly when taken in conjunction withthe accompanying drawings showing. by way of example a preferredembodiment of the inventive idea.

In the drawings:

Figure 1 isa top plan view of the self-centralizing arbor for plugcgages rotatably mounted between head and tail stocks and constructed inFigure 2is a, top plan view of the self ntr'ali'zing arbor shown inFigure l but; on annlarged scale and v Figure 3 is an endview of theself-centralizh1g7 arbor'shown in Figure Zt Referring? now in greaterdetail to the drawccordain'ce with the principles of this invert;-

Inc's where like reference numerals indicate like {:ia'rts referencenumeral I O ixid-icates th'eplug gage w be" t'rued, and H- theself-centralizing arbor for aiding inthe-tru-ing or the plug gage.

The plug gage m is a d namic-ai metallic body havin a-longitudinalopening I 2 61 circular cross sectiors-thmugh-the ends at the centei;The opening 12 at both ends terminates in similar openings or-recessesl3 and I4 of circular cross end' of the gage;

section and enlarged diameter relative to the longitudinalopening. Thegagejfl is roughly threaded in a known manner and then case hard ened.Variations in the internal structure of the-crystals forming themetallic gage under the influence of the threadingand case hardeningoperations necessitates that the plug be trued,= a task now performed byhighly skilled personnel using arotatable grinding wheel. y, The arbor His constituted of a shaft 15 fitted through the previously mentionedopening I! of the gage. Since some adjustment of the gage Ill on thearbor H is imperative;- a reasonable tolerance is provided between theoutside diameter of the shaft and the inside; diameter of the gage.- H Ap a Adjacent one end l'l; (Fig, 2) of the shaft 12 is a cylindricalflange I6, integrally formed with the shaft or otherwise attachedthereto. 0n the inner face of the flange Is, that is the face 09-posi-te to the end H, is acylindrical shoulder or protrusion I8 ofreduced diameter. The diameter of the protrusion I8 is designed for fitting into the circular recess [3 of the plug gage with suitabletolerance between the members to permitadjustment as later shown;

V Threaded transversely through the rim of the flange [6 are threeadjustment screws 19, 20, and 21,- the center lines of the screws beingparablel to the center lineof' the arbor and circum-= ferential-lyspaced apart in the flange 120". It will be noted that the ends of thescrews when threaded through the flange are in contact with or may bebrought in contact with the opposed A-lso threaded through the flangel-G as well as the sides of the integrally formedprotrusion i8 are threemore screws 22;

are inclined to' the center" line of the-arbor.- The" innerends of thescrews 22-; 23; and 24* have an'g'u lar inner ends to contact the sidesof the recess" l3 of the gage ill at three points spaced also 120 apart.

At the sameend I l of theshaft I5 is a conicalrecess 28 for mounting theshaft [5- on the shaft 25 of the head stock 30, described infra. Inaddition, the shaft- 5 at the same" end has aflattened surface portion 26 which is in a plane parallel to theeenter line of the shaft l'5.

Over the opposite or threaded" end of the" shaft I5 is a cylindricalwasher 21 constituting the othensideof theclamp or jaw member holdii'igage w-inc'oaction with the aforementionedflange I 6. Removably holdingthe washer 21 against the free end of the case is a nut 29 on 3 thethreaded end of the shaft IS. A conical recess 46 in the center of thethreaded end of the arbor at the same end provides the means forpporting that end of the arbor by the t il stock 3|.

The head stock 30 and tail stock, are known. The arbor H is rotated bytheJhead stock in the following manner: A stop 41 i longitudinallyattached to the lath head 48 by any suitable screws 49, the stop 41being extended beyond the end of the lath head. The extended end of thestop- 41 serves as a stop for the L-shaped driver 32 removably securedon the end of the shaft 25 of the lath head by a screw 33. The end ofthe horizontal portion of the L-shaped driver is removably securedthrough the end of a split dog 50 in turn removably attached to theflattened surface 26 of the shaft l5 by a screw 34.

Indicating whether any point on the outer surface of the threaded pluggage I9 is high or low relative to the center line of the arbor'is astandard indicator 39 which may be in the form of a dial having arotatably mounted pointer over any arbitrarily chosen scale, as shown.Actuating the pointer is an arm 37 reciprocally mounted by any suitablemeans in a plane perpendicular to the center line of the arbor, the armbeing reciprocally actuated by the handle member 38 interconnected in aknown manner with any suitable mechanism. In the end of the arm 31adjacent theplug gage I is a ball point 36 along the center line of thearm extended. The ball point may be attached to the arm in any desiredmanner. Of course, the indicator 39 is independently mounted from thearm and the means revolving the pointer of the indicator may be the wellknown rack and pinion combination, not shown.

Indicating whether any point on the outer surface of the threaded pluggage I0 is high or low relative to the ends of the arbor is anotherindicator 45 similar to the previously mentioned indicator 39. Theindicator 45 is actuated by a lever 4| pivotally mounted by any suitablemeans 42 in a plan through the center line of the arbor. In the weightarm of the lever 4| is a ball point 49, protruding from the end thereofand coacting with the threads of the plug. The lever arm is movedlongitudinally by the handle 43 interconnected with the lever throughany known slide and slideway combination. Coacting with the power arm ofthe lever, is a slidably disposed member 44 under outwardly directedtension, the opposite end of which may have a rack in operableengagement with the pointer on the dial as in the first embodiment.Moving the lever transversely relative to the gage is a handle "memberf46 through any suitable means at the end of which the slideway for thelongitudinal movement of the lever 4 l' is mounted. The indicator 45 andassociated mechanisms previously described is also essentially asynchronizing device for a number of gages to be trued at one time.While the nut 29 is only finger tight and the driver 32 rests againstthe stop 41, by turning the gage I0 until the indicator 45 reads zerothe V of the thread at the ball point will be synchronized with the flatsurface 26 so that the position of the grindin wheel relative to thethread of each successive plug will be the same.

- In operation: The gage l3, roughly threaded and case hardshed, isinserted over the shaft l of the arbor Ill the gage.

4 and against the flange I 6 with the shoulder 18 in the recess of thegage. The washer 21 is then inserted over the threaded end of the shaft15 and the nut 29 threaded on the shaft against the outer end of thewasher 21 to securely hold The arbor is then insertedbetween the pointedends of the shafts of thehead and tail stocks with the end of the shaftI5 having the flattened surface 26 through the split dog 32 and thescrew 34 tightened, assuming, of course, that th dog has already beenattached to the driver and the driver to the shaft 25 of the head stockin the manner previously described. By rotating the handle 38, the ballpoint 35 of the indicator 39 can be tested against the threads until anapproximate low point is found and to which the remainder of the surfacemust be ground down. By manipulating the handles 43 and 46 of theindicator 45 along various points of the gage another point may be foundthat appears low relative to the end of the gage. By manipulation of theangularly disposed screws 22, 2 3, and 24 of the dial 39, the pointer atthe-selected point can be brought back to zero on the scale, even thoughthe selected low point reads 2 points off at zero. To the adjustedposition of the dial all other points must be made to conform bygrinding. In a similar manner the arrow of dial 45 is brought back tozero but by the manipulation of the screws I9, 20, and 2|. With thepredetermined knowledge of the high and low spots on the gage, thegrinding operations are greatlyfacilitated. It will be understood thatthe invention is not limited to the exact disclosure herein describedbut may lend itself to a variety of expressions within the scope of theappended claim.

What is claimed is: p A self-centralizing arbor for a plug a gage having a cylindrical opening terminating at each end in recesses of greaterdiameter, said arbor comprising a shaft adapted to be inserted into theopening of the gage, a cylindricalflange mounted on said shaft adaptedto engage one end of the gage, a cylindrical shoulder connected withsaid flange and adapted to fit into one of said recesses, a plurality ofscrews threaded through said flange above said shoulder and extendingparallel to the longitudinal axis of the arbor, said screws beingadapted to engage said one endof the gage, and other screws threadedthrough said flange and said shoulder at an acut angle to said axis andadapted to engage the inner surface of said one recess.

References Cited in the file of this patent UNITED STATES PATENTS Number2,433,743 Dickens Dec. 30,1947-

